Inhaled corticosteroids are the most commonly used anti-inflammatory agents used for chronic asthma therapy. Although increasing use of high-dose inhaled corticosteroid therapy has raised concerns about the potential for adverse effects with long-term use, standard doses of corticosteroids given by inhalation appear to be safe and effect. Inhaled corticosteroids are felt to modify the disease process; there is evidence of asthma control even after inhaled corticosteroids are reduced or stopped. A long-acting inhaled beta-agonist, salmeterol induces bronchodilation and may have anti-inflammatory properties. While early studies of the regular use of salmeterol suggest that it reduces the symptomatic severity of asthma, the importance of its bronchodilating versus anti-inflammatory activities is not known. Studies to date have found no deleterious effects of long-term use of salmeterol. This study will test, in patients with moderate asthma, whether the addition of inhaled salmeterol can reduce or eliminate inhaled corticosteroids over time without concomitant increase in asthma symptoms or a decrease in protection against methacholine induced bronchoconstriction.